Spin machine with several single drives

ABSTRACT

In a spinning machine with at least one spinning station ( 1 ) which station possesses a feed drum ( 2 ), driven by a single drive ( 12 ), a disintegrator ( 3 ), a rotor ( 4 ), a withdrawal roll ( 5 ) and a spool roll ( 7 ), provision has been made, that the spinning station ( 1 ) has an additional single drive ( 15, 16, 17 ) respectively for the withdrawal roll ( 5 ) and/or the spool roll ( 7 ) and/or a paraffin roll ( 6 ) and that the speed of rotation ratio of the single drives ( 12, 15, 16, 17 ) can be preset to specified values.

[0001] The invention concerns a spinning machine with at least onespinning station, which station possesses a feed drum driven by a singledrive, a disintegrating roll, a rotor, a withdrawal roll and a spoolroll.

[0002] EP 0 385 530 discloses such a spinning machine, in which the feeddrum of each spinning position of an open-end spinning machine is drivenby means of a stepping motor. A control system with an associatedcomputer regulates the corresponding stepping motor in each spinningmachine in accord with its direction of rotation, its speed of rotationand the angular position of the drive, and thereby also the feed drum. Acontrol system for each of the stepping motors is advantageous, so thatthe necessary precision in regard to the feed of the fiber band isassured.

[0003] In the conventional spinning machines, normally, the rotatingelements which follow the feed drum in the direction of the bandmovement, for example, the rotor, are centrally driven by means ofmotors provided on an end of the spinning machine. In order to achievethe necessary correlation of the speed of rotation, for instance, of thefeed roll, the withdrawal roll, and the spool roll, it is usual toprovide electrically controlled, mechanical gear drives. By this means,each spinning station can produce constant thread quality where threaddiameter and strength is concerned. Such gear drives possess, however, agreat number of points of abrasion, which give rise to a relativelysubstantial demand of expense and maintenance time. Additionally, arelatively large startup momentum can be attributed to these geardrives. Where the necessary electrical control is concerned,considerable costs are involved in the wiring and its installation.

[0004] Thus, it is the purpose of the invention, to make available aspinning machine of the kind mentioned in the introductory passages, inwhich is made possible a simple, and therefore precise, drive of theindividual rotational elements of a spinning station.

[0005] This purpose, in the case of the spinning machine of the kindmentioned in the introductory passages, is achieved, in that thespinning station exhibits, respectively for the withdrawal roll, and/orthe spool roll, and/or the waxing roll, an additional single drive, andthat the rotational ratios of the single drive can be set tospecification.

[0006] The advantage of the invention can be particularly seen inthat—besides each feed drum—an individual drive has been assigned toeach withdrawal roll, and/or to the spool roll, and/or to for waxingroll. Since the rotational ratios of the individual drives of eachspinning station can be specified, an optimized correlation in regard tosynchronization, operational life, and rotational speed is assured.Furthermore, by means of the installation of the single drives,expensive, and thereby damage-prone gear drive construction is avoided,which otherwise would extend itself over the entire length of thespinning machine. Another advantage is that with this single drive, avery low degree of nominal torque is present, because of the smallfriction to which the individual drives are exposed. Especially, notorsional delays occur upon the startup of the respective rotationalelements of the spinning stations, which are situated remotely from thecentral motor. A single drive, as an example, is also advantageous forthe withdrawal roll, since this, upon spin-startup is driven in reversedirection, so that the spinning startup process is made substantiallymore easy.

[0007] Advantageously, one of the individual drives serves as a leadmotor. This has a specified guiding rotational speed or a specifiedguide frequency, to which is related the rotational speed of at leastone single drive, and preferably, where multiple drives are concerned,the rotational speeds of all other single drives. In this manner, theRPM of all other single drives refers back to the said lead drive andthe rotational speeds of the other drives can thus be preset.

[0008] Particularly advantageously, the feed motor of the feed drum isdesignated to be the guide motor, since first, this rotates at arelatively low rotational speed (1-150 RPM) and second, must hold to thecurrently set rotational speed with great precision. Even smalldeviations lead to an undesirable variation of the set values of thethread to be spun. Although the single drive of the feed drum is chosenas the lead motor, this is not dependent upon the guidelines of otherdrives. Much more, rotational speed of the lead motor can be directlyand precisely adjusted. Because of the mentioned achievable exactness ofits rotational speed, with an appropriate ratio control, a uniformtorque for the other single drives is possible in all RPM ranges.

[0009] In an advantageous manner, for each spinning station, only onepower control center for the regulation and the supply of electricalcurrent to the individual drive need be provided. This design has theadvantage, that the electronic circuitry need be installed only once,since this serves in common for all individual drives per spinningstation. On this account long cable hook-ups from a central network,which then must run along the entire spinning machine, are no longernecessary.

[0010] In order to further reduce extensive constructional work andwiring, the power control center is placed on or near one of theindividual drives. For instance, the power control center is screwedwithin or onto the housing of the feed drum. For the wiring thereof,corresponding borings are made through the housing. From the powercontrol center, the additional control and power lines run to the otherindividual drives. Principally, the power control center can be providedat any of the other individual drives. For the eventual placement, thespatial conditions in the spinning station must be taken intoconsideration, so that, besides space saving, maintenance and cleaningservices can be carried out with good accessibility.

[0011] The rotational speed of the other single drives, in relation tothe lead motor, is advantageously effected by a frequency generator. Forinstance, there is respectively one frequency generator between thepower control center, to which the lead motor is connected, and any ofthe single drives which is to be controlled. Alternatively, simply asingle frequency generator can be furnished which transmits to theindividual drives, by means of a frequency divider, the rotational speedcommands based on those of the lead motor.

[0012] The invention allows, that a very fine subdividing of the motorrotation speed for the lead motor and/or the individual drives, may beundertaken in micro-stepping, so that practically, feedback-freeoperation of this motor is possible.

[0013] Particularly advantageous is to design at least one of the singledrives as a stepping motor. Stepping motors have the advantage, thatthey possess only very few parts, and certainly no gear drives which aresusceptible to wear and tear. Further, stepping motors possess theadvantage, that, while maintaining high efficiency, a relatively smallinertial moment is in effect, wherein, their shafts start to rotatewithout inrush current to the motor, that is, the motor can be quicklyaccelerated. In addition, stepping motors can be simply and preciselycontrolled and react very quickly to control commands. Further, steppingmotors can be brought up to top speed on a continuous basis and inaddition can be driven in the reverse direction. In regard to theeconomics, the stepping motor has no decisive disadvantage as comparedto the synchronous motor. By the use of a stepping motor for the feeddrum, this motor is preferable in a range of 1 to 150 RPM and can be runat a nearly constant torque.

[0014] Especially at a paraffin roll, which serves for the waxing of thethread before the windup on the spool, the installation of a steppingmotor is of advantage. Conventionally, for the drive of a paraffin roll,a synchronous motor is selected. On the grounds of the mechanical geardrive in such a motor, during startup of the roll, relatively greatfrictional forces must be overcome. To this purpose, the motorcustomarily calls for excess current. This characteristic increases thecomplexity of the control, i.e. of constant monitoring. Alternatively, alarger motor could be selected, which, however would have an evengreater demand for current at startup. By means of the selection of astepping motor, all these problems are prevented.

[0015] For the feed drum of each spinning station, the use of a steppingmotor is likewise of advantage, as has already be made plain by theabove description of the state of the technology. In particular, thedoing away with extensive and failure-prone gear drives, as well asacquiring precision of the RPM even in the lower rotational speed rangesare advantages to be valued.

[0016] This said precision permits running the spinning station as a“stand alone machine” with the corresponding demands for a high degreeof precision. The installation of stepping motors for the individualdrive of the withdrawal roll and/or the spool roll—if such individualdrives are provided—is, because of the above mentioned grounds, alsoadvantageous.

[0017] In a particularly preferred embodiment of the invention, thestepping motor for the paraffin roll is regulated by the lead steppingmotor of the feed drum, in that a power control center delivers a signalthrough the frequency generator and over a line to the stepping motorfor the said paraffin roll. Should the feed drum, for instance, beturning at 10 RPM and if the frequency generator is set at a rotationalspeed ratio of 5:1, then the paraffin roll rotates at 2 RPM. In such anoperation, advantageously, small micro-step subdivisions per motorrevolution are not necessary.

[0018] Advantageous developments of the invention are characterized bythe features of the subordinate claims.

[0019] In the following, an embodiment of the invention will be moreclosely described with the aid of the drawing. In this FIGURE a spinningstation 1 of a spinning machine is schematically presented. With aplurality of similar spinning stations 1, these are customarily placedbeside one another, which, in composite, form the spinning machine. Thespinning station 1 possesses—in the direction of travel of the fiberband—in sequential array:

[0020] a feed drum 2

[0021] a disintegrator 3

[0022] a rotor 4

[0023] a withdrawal roll 5

[0024] a paraffin roll 6 with auxiliary

[0025] paraffining block 8 and

[0026] a spool roll 7

[0027] Emerging from a (not shown) stretch works, the fiber band B makesits way to the feed drum 2, which is circumferentially and axiallycorrugated and which conveys the fiber band B to the disintegrator roll3.

[0028] Equipped with circumferential comblike teeth 13, thedisintegrator separates the band B into individual fibers. By means of afunnel shaped conduit 14, and under a suction, the stream of individualfibers enters the rotor 4. The rotor 4 rotates, by means of a centraldrive for all rotors of the spinning machine, at speeds of rotationexceeding 100,000 RPM and spins the fibers into a thread F. This threadF is subsequently removed from said rotor by the withdrawal roll 5together with roll 11 which exerts a rolling pressure on the withdrawalroll 5. After this the thread F is guided to frictional contact with theparaffin block 8 and then is transported by the paraffin roll 6, whichturns at a low rate of speed. Continuing in motion the thread is finallywound onto a spool 10 which is axially supported by a rotating core 9.The spool 10 lies with its own weight against the spool roll 7 andobtains its rotational energy therefrom.

[0029] The feed drum 2 is connected to an individual drive 12 designedas a stepping motor. In the embodiment presented in the figure, thewithdrawal roll 5 is connected with a single drive 15, the paraffin roll6 with a single drive 16 and the spool roll 7 with its own drive 17. Thestepping motor for the feed drum 2, in the depicted embodiment, isdesigned a lead motor with a specifically set lead RPM or with a givenlead frequency. This said lead RPM determines the RPM of the remainingdrives 15, 16 and 17. The speed of rotation of the motor 12 iscontrolled by a power control center 20, which with the input of eitherthe specified lead frequency or the lead speed of rotation of said motor12, transmits the respective frequencies (or RPM's) to the saidindividual motors 15, 16, 17 by means of electrical lines 23, 25, 27.Between the power control center 20 and the individual drives 15, 16,17, respectively, a frequency generator 22, 24, 26 is inserted into thecircuit, for the purpose of presetting to specific values the speeds ofrotation of the single drives 15, 16 17.

[0030] The individual drives 15, 16 17 can be designed as steppingmotors, in like manner to the individual drive 12 of the feed drum 2.Stepping motors have, in such an application, among other preferablefeatures, the advantage that they possess no gear drives subject to wearand tear. The supposed disadvantage, that stepping motors must bedirectly controlled, was countered by the invention, in that simply asingle power control center is provided, by means of which, therotational ratios—derived from either the frequency or the RPM of a leadmotor—can be preset to specified values.

[0031] The single power control center 20 serves likewise for the powerdistribution to the individual drives 12, 15, 16, 17. Not only does thisallow space to be saved within the spinning station, but also theexpenditure in wiring and attendant labor within a spinning station canbe held at a low level. The power control center 20 is, for instance,placed directly on the stepping motor 12 of the feed drum 2. possiblyscrewed onto the housing thereof. From this point the electrical controllines 23, 25 27 run respectively to the other individual drivesassociated with the given spinning station. The frequency generators 22,24, 26 can likewise by incorporated into the power control center.

[0032] In an embodiment which is not illustrated, another motor isproposed as lead motor instead of the individual motor 12 of the feeddrum 2. In the case of additional, not shown, embodiments, besides theindividual motor 12 for the feed drum 2, simply one or two of theindividual drives 15, 16, 17 are foreseen as the drive of one or two ofthe rolls 5, 6, 7. Especially, the possibility exists of using anindividual drive 16, designed as a stepping motor, for the paraffin roll6 and to control this by the individual drive 12 for the feed roll 2 bymeans of the power control center 20 as well as with the frequencygenerator 24. In this manner, no problems will arise upon startup of theparaffin roll 6, since lesser frictional force is to be overcome than isthe case with the conventionally employed synchronous motor. Thus anotherwise necessary, heavy inrush current at startup for the paraffinroll can be avoided. Moreover, a single drive 16 for the paraffin roll 6shows little wear, so the maintenance and cleaning expenses are kept ata low level.

1. A spinning machine with at least one spinning station (1) whichstation possesses a feed drum (2) driven by a single drive (12), adisintegrator (3), a rotor (4), a withdrawal roll (5) and a spool roll(7), therein characterized, in that the spinning station (1) possessesadditional single drives (15, 16, 17) respectively for the withdrawalroll (5) and/or for the spool roll (7) and/or for a paraffin roll (6)and in that the speed of rotation ratios of the single drives arecapable of being preset to specified values.
 2. A spinning machine inaccord with claim (1), therein characterized, in that one of the singledrives (12, 15, 16, 17) is designed to be a lead motor operating with apreset speed of rotation or a preselected rotational frequency for atleast one other single drive.
 3. A spinning machine in accord with claim2 , therein characterized, in that the single drive (12) of the feeddrum (2) is designed to be a lead motor with a preset speed of rotationor a preselected rotational frequency.
 4. A spinning machine in accordwith one of the foregoing claims, characterized by a power controlcenter (20) assigned to each spinning position (1) for the regulationand electric current supply of the single drives (12, 15, 16, 17).
 5. Aspinning machine in accord with claim 4 , therein characterized, in thatthe power control center 20 is placed on or near one of the singledrives (12, 15, 16, 17).
 6. A spinning machine in accord with one of theclaims 2 to 5 , therein characterized, in that of the single drives (12,15, 16, 17) the lead motor thereof is connected to the others by atleast one frequency generator (22, 24, 26), wherewith the preset speedof rotation ratios of the single drives (12, 15, 16, 17) can beimplemented.
 7. A spinning machine in accord with one of the foregoingclaims, therein characterized, in that at least one of the single drives(12, 15, 16, 17) is designed as a stepping motor.
 8. A spinning machinein accord with one of the foregoing claims, therein characterized, inthat the single drive (16), designed as a stepping motor for theparaffin roll (6) follows the lead stepping motor (12) for the feed drum(2) by means of a power control center (20) as well as a frequencygenerator (24).